Hi Roberto,
While we have discovered a minor issue with the installation instructions for 2.7 (outlined
here; docs are in the process of being updated right now), in your case this particular thing doesn't seem to be the issue.
In the vast majority of posts I see like this, with Column not found errors during an upgrade, it is because a critical step of the upgrade process was skipped. Usually, it is the step to drop and then recreate the database BEFORE loading your sqldump; occasionally it is because the upgrade task was not run AFTER loading the sqldump.
Did you drop and recreate the database before loading your backed up data, as described in step 4 of this section?
If not, please try repeating the upgrade process and let us know how it goes!
If yes, did you remember to run the upgrade task after loading?
If you're not sure, you can try running it again - it should not break anything if your installation's database schema version is already up to date. If you do run it again however, make sure to follow some of the other maintenance steps in the docs following that, such as restarting services, repopulating the search index, etc.
Cheers,